How can I apply Newton's First and Second Law to walking?
I'm thinking the 1st, is the muscles would apply an unblanced force to make us move?
Second-if we're walking and the mass of our body is 130 lbs and we're accelerating at 4 miles per hour, then the force necessary to keep us in motion would be 520
Please give me any feedaback that you could provide-I need to draw diagrams and everything but I do that once I get a feel. I know the two laws, I just don't get how to aplly them
I think I would avoid the muscles.
Feet on the ground.
newtons first Law: consider if it were on ice? if frictionless, the person would stay in motion (still). but with friction, the shoes can apply a force on the pavement, and the pavement can apply a force on the shoes, allowing motion.
Second law: when turning direction, shoes apply a sideways force, causing a new acceleration (change of direction).
Third law: for every force the shoe applies, the pavement applies an equal and opposite force.
Thanks alot I really appreciate it
To apply Newton's First and Second Law to walking, let's break it down step by step:
1. Newton's First Law (Law of Inertia): This law states that an object at rest will stay at rest, and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an external force.
When you are at rest and want to start walking, your body is initially in a state of rest. According to Newton's First Law, you need an external force to overcome inertia and set your body in motion. In this case, the muscles in your legs provide the force needed to overcome inertia and initiate walking. The unbalanced force generated by your muscles pushes you forward and gets you moving.
2. Newton's Second Law (Law of Acceleration): This law states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass.
When you are already walking, Newton's Second Law comes into play. The force responsible for your continuous acceleration while walking is the force produced by your leg muscles. This force is exerted against the ground, and according to Newton's Third Law, the ground exerts an equal and opposite force (friction) back on you. This friction force is what propels you forward and allows you to keep walking with a constant speed.
To calculate the force necessary to keep you in motion, you need to consider the mass of your body (130 lbs) and the acceleration (4 miles per hour).
First, convert your mass from pounds to kilograms (since the standard SI unit of mass is kg):
130 lbs = 130 lbs × 0.4536 kg/lb (approx.) = 58.9 kg (approx.)
Next, convert the speed from miles per hour to meters per second (since the standard SI unit of speed is m/s):
4 miles per hour = 4 miles/hour × 1.60934 km/mile × 1000 m/km × 1/3600 hour/second (approx.) = 1.79 m/s (approx.)
Now that you have the mass (58.9 kg) and acceleration (1.79 m/s), you can use Newton's Second Law formula:
Force = mass × acceleration
Force = 58.9 kg × 1.79 m/s = 105.23 N (approx.)
So, the force necessary to keep you in motion while walking at an acceleration of 4 miles per hour is approximately 105.23 Newtons.
Remember, these calculations are approximate and depend on various factors like body posture, walking style, and surface conditions.